CN110965389A

CN110965389A - Paper softener composition

Info

Publication number: CN110965389A
Application number: CN201811153667.XA
Authority: CN
Inventors: 谷敬坤; 赵成英
Original assignee: Elkem Silicones Shanghai Co Ltd
Current assignee: Elkem Silicones Shanghai Co Ltd
Priority date: 2018-09-30
Filing date: 2018-09-30
Publication date: 2020-04-07
Also published as: KR102650260B1; KR20210053313A; CN112888746A; JP7228745B1; WO2020063836A1; JP2023036720A; JP2022503976A

Abstract

The present invention relates to a paper softener composition, a method of treating paper with the softener composition and paper products treated with the softener composition. The softener composition comprises 0.1 to 20 wt% of an aminopolysiloxane of formula (I) below and 10 to 80 wt% of a monohydric or polyhydric alcohol, wherein the weight ratio of the aminopolysiloxane to the polyol is 0.2 to 0.001.

Description

Paper softener composition

Technical Field

The present invention relates to a paper softener composition, a method of treating paper with the softener composition and paper products treated with the softener composition.

Prior Art

In modern life, people have higher and higher requirements on softness of paper. Therefore, it is increasingly important to use suitable softeners to improve the softness of paper. Here, the "paper" particularly means a paper product for daily use such as wet tissue, handkerchief paper, napkin paper, beauty paper, box tissue, etc., which generally have certain requirements for softness, fluffy feeling, water absorption, etc.

Paper softener products are typically made from quaternary ammonium salts, lubricants, or silicones, and the like. They are typically applied to the surface of the paper by brushing, rolling or slurry addition.

For example, CN101509213A discloses a bisamide quaternary ammonium salt paper softener, and a preparation method and application thereof.

In addition, the effect of different cationic softeners on paper was compared in "the effect of different cationic softeners on the performance of household paper" by the Yankee company, et al (cellulose science and technology, Vol.23, No. 1, 3 months 2015). These cationic softeners include imidazolines, polyacrylamides, quaternary ammonium salts, fatty acid esters, and silicones, and the comparative results show that amino-containing silicone softeners have the best performance for softness.

However, in addition to the improvement in softness of paper, manufacturers of paper, particularly wet wipes, are also paying more attention to the skin-friendly property of paper after treatment with a softener (particularly, the skin is easily irritated in the case of an amino group-containing silicone compound), and how to increase the amount of the softener to be applied to reduce the production cost and save raw materials, while keeping softness and strength of paper as low as possible.

In another document CN103061204B, a softener emulsion composition is disclosed which comprises inter alia diorganopolysiloxane, monohydric or polyhydric alcohol-containing humectant and thickener. The recommended coating amount of the softener emulsion composition is 1% to 20% based on the weight of the base paper, and a thickener must be included in the composition. Furthermore, this document does not disclose any specific diorganopolysiloxane compound.

In addition, a novel piperidinyl organosiloxane is disclosed in US 5721297A. However, the only use of said organosiloxanes as light-and UV-resistant stabilizers for polymeric substrates, such as polyethylene or polydienes, is in this document.

Summary of The Invention

In view of the above-mentioned object, the present application provides a softener composition according to claim 1, which comprises a combination of a specific aminopolysiloxane with a monohydric or polyhydric alcohol in a specific quantity ratio. Surprisingly, the inventors of the present application have found that with such a softener composition, improvement in softness and increase in coating amount can be achieved without impairing the strength of paper. In particular, the application amount of the softener composition can be increased to an amount of 20% or more on the basis of the paper without adding additives for improving viscosity, such as thickeners.

Furthermore, according to the softener composition of the present invention, since a combination of an aminopolysiloxane and a monohydric or polyhydric alcohol in a specific ratio is used, the improvement of softness under the synergistic effect of these two components is more effective than in the case of a polysiloxane system alone or an alcohol system alone. Further, the softener composition according to the invention enables the paper treated therewith to still maintain good water absorbency, be less prone to yellowing and have good skin substantivity.

In another aspect, the present application is also directed to a method of processing paper.

Finally, the present application relates to a paper product obtained according to the above-mentioned method.

Detailed Description

Aminopolysiloxanes (also commonly referred to as amino silicone oils) are known as softeners for paper treatment. Such an amino-modified organosilicon compound is a polysiloxane having an amino group in a side chain or a terminal group thereof. Because oxygen atoms in the siloxane bonds in the main chain can be adsorbed on the fiber surface, hydrophobic groups can be directionally arranged along the fiber surface of the paper, and a hydrophobic and stretchable continuous film is formed on the hydrophobic and stretchable continuous film, so that the paper is softer. However, the conventional amino polydimethylsiloxane is irritant to skin and eyes, and meanwhile, the treated paper is easy to yellow under high temperature and external conditions, so that the shelf life of the treated paper is shortened. The water absorption properties of the treated paper are significantly reduced due to the water repellency of the polysiloxane film.

However, the inventors of the present application have found that when a specific aminopolysiloxane as described below is used in combination with a monohydric or polyhydric alcohol, in particular a polyol compound such as glycerol, a further significant improvement in softness and a large increase in coating weight can be achieved while maintaining mechanical properties without being impaired or even improved. In addition, the treated paper keeps the water absorption of the base paper, and the treated paper towel is not easy to yellow and discolor and has good skin affinity.

Thus, the softener composition according to the invention comprises, based on the total weight of the composition:

-from 0.1 to 20% by weight, preferably from 0.5 to 15% by weight, more preferably from 1.0 to 10% by weight, of an aminopolysiloxane of formula (I);

wherein

p and r are numbers greater than or equal to 0;

q is a number greater than 0, preferably from 1 to 40; and preferably the sum of p + r + q is greater than or equal to 5;

r represents a linear or branched alkyl or alkoxy group having 1 to 12, preferably 1 to 6, carbon atoms or represents a hydroxyl group;

R₁represents a linear or branched alkyl or alkoxy group having 1 to 18, preferably 1 to 12, more preferably 1 to 8 carbon atoms or represents a hydroxyl group,

R₂represents a linear or branched alkylene group having 1 to 18, preferably 2 to 12, carbon atoms;

R₃represents a hydrogen atom or a linear or branched alkyl group having 1 to 18, preferably 2 to 12, carbon atoms;

z represents-O-or-NR₈-, wherein R₈Having R₃The definition of (1); and

10-80% by weight, preferably 20-75% by weight, more preferably 25-75% by weight of a mono-or polyhydric alcohol;

wherein the weight ratio of the aminopolysiloxane to the monohydric or polyhydric alcohol is from 0.2 to 0.001.

In an advantageous embodiment according to the invention, the preferred aminopolysiloxanes of formula (I) satisfy at least one of the following conditions:

p and r are each independently 1 to 1000, such as 2 to 800; q is 1 to 30; the sum of p + r + q is 10-2000, more preferably 100-; r and R₁Independently of one another, methyl, ethyl, propylMethoxy, ethoxy or hydroxy; r₂Represents ethylene, propylene, butylene, pentylene or hexylene; r₃Represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group or a propyl group; and/or Z represents-O-or-NR₈-, wherein R₈Is a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms such as methyl, ethyl or propyl.

In a more preferred embodiment, R and R in the aminopolysiloxanes of formula (I)₁Independently of one another, from methyl, ethyl, methoxy or hydroxy, more preferably methyl; r₂Represents ethylene, propylene or butylene, more preferably propylene; z represents-O-; and/or R₃Represents a hydrogen atom.

The aminopolysiloxanes of formula (I) according to the invention can be prepared from organosiloxane compounds of the following formula (II):

wherein p, q, R, R and R₁Have the corresponding meanings as given above for the compounds of the formula (I). Preference is given here, as starting material, to compounds of the formula (II) in which at least one radical R is present₁Is CH₃。

Such compounds of formula (II) are readily commercially available.

The hydrogen atom of the compound (II) being substituted by a group of the formula (III)

And optionally by a group R₁The substitution of (b) can be achieved by reacting the organosiloxane (II) with a compound having a vinyl double bond which is liable to undergo a hydrosilylation reaction in the presence of a catalyst.

Thus, such a compound would be the group (III) or the group R₁Of (4) an unsaturated precursor of (a).

Specific non-limiting R₁Examples of unsaturated precursors of (A) are 1-Octene, 1-dodecene and 1-octadecene.

Specific non-limiting examples of precursors of the group of formula (III) are 1-allyloxy-2, 2,6, 6-tetramethylpiperidine, 4-allyloxy-1, 2,2,6, 6-pentamethylpiperidine and 2,2,6, 6-tetramethyl-4-piperidylundecenoate.

It is also possible to use groups R which contain vinyl double bonds₂Via hydrosilylation on the ≡ Si-H moiety, followed by R here₂To introduce 2,2,6, 6-tetramethyl-4-piperidyl thereon, thereby forming the following structural unit:

the synthetic routes for the different compounds of formula (I) according to the invention can be varied and are not restricted here. For example, the person skilled in the art can refer to and modify the synthesis of the piperidyl organosiloxanes described in the prior art US5721297A to obtain compounds of formula (I) having the desired structure. US5721297A is hereby incorporated by reference in its entirety.

The aminopolysiloxanes of formula (I) which are particularly suitable according to the invention are commercially available here as BLUESIL FLD21650, BLUESIL FLD 21653, BLUESIL FLD 21654, etc.

In particular, the inventors of the present application have found that, when the aminopolysiloxanes of formula (I) according to the invention are included in the composition, in addition to maintaining the mechanical properties without impairment and achieving a further significant improvement in softness, the aminopolysiloxanes of formula (I) can lead to better water absorption and improved resistance to yellowing of the treated paper, in particular also bringing about good skin substantivity, compared to other commonly used aminosilicones. It is therefore preferred that the composition of the invention comprises only the aminopolysiloxane of formula (I) as silicone component, while the content of other organosilicon compounds, in particular of other aminopolysiloxanes, does not exceed 5% by weight, preferably does not exceed 2% by weight, more preferably does not exceed 1% by weight, and especially preferably does not exceed 0.5% by weight, based on the total weight of the composition.

As another component of the softener composition of the invention, a monohydroxy or polyhydroxy alcohol compound is used. Suitable monohydric or polyhydric alcohols are understood within the scope of the present invention as compounds having on average one or more hydroxyl groups per molecule, preferably aliphatic or polyether alcohols.

In one advantageous embodiment, suitable monohydroxy or polyhydroxy alcohol compounds may be of the formula A- (OH)_z，

Wherein z represents an integer of 1 to 6, preferably 1 to 4, more preferably 2 to 3;

a represents an aliphatic group having 1 to 12 carbon atoms, preferably 2 to 8 carbon atoms, more preferably 3 to 8 carbon atoms, such as an alkyl group, or represents a polyether segment having a molecular weight of 40-1600.

Preferably, the polyether segments are aliphatic polyether segments, preferably selected from segments having from 4 to 25 polyoxyethylene and/or polyoxypropylene groups.

Here, the position of the hydroxyl group is not limited, and it may be at the end or lateral of the group a.

Preferably, examples of the monohydric or polyhydric alcohol compounds according to the present invention include ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, ethylene glycol, propylene glycol, glycerol, diethylene glycol, trimethylolpropane, hexanediol, polyether polyols such as polyoxyethylene or polyoxypropylene diols or triols, and the like. Preferably, the monohydric or polyhydric alcohol compound is selected from ethylene glycol, trimethylolpropane, propylene glycol and/or glycerol. The inventors of the present application have found that if glycerol (glycerin) is used in the composition as the monohydroxy or polyhydroxy alcohol component in the composition, this can result in better softness, smoothness and moisture retention of the paper after treatment.

Thus, in a particularly preferred embodiment, the monohydric or polyhydric alcohol component comprises at least 95 wt.%, preferably at least 98 wt.%, more preferably at least 99 wt.%, particularly preferably 99.5 wt.% or even 100 wt.% of glycerol.

Further, in order to achieve the above effects of the present invention, the weight ratio of the aminopolysiloxane to the polyol component must be in the range of 0.001 to 0.2. If the weight ratio is outside this range, it results in deterioration of the hand of the treated paper and lowering of the moisturizing property, and may even affect the mechanical properties and the coating amount thereof. Advantageously, the weight ratio of the aminopolysiloxane to the monohydric or polyhydric alcohol is controlled in the range from 0.001 to 0.2, preferably from 0.002 to 0.15, more preferably from 0.005 to 0.10, particularly preferably from 0.01 to 0.08. Within the most preferred ranges and preferably in combination with the substantial use of glycerol as the monohydric or polyhydric alcohol component, the treated paper is capable of exhibiting the best overall properties.

Furthermore, in an advantageous embodiment, an emulsifier may also be included in the softener composition according to the invention to form a stable emulsion, facilitating the coating of paper. Such emulsifiers may be nonionic emulsifiers and cationic emulsifiers. Examples of suitable nonionic emulsifiers include the polyoxyethylene ethers of fatty alcohols, such as polyoxyethylene ethers having 4 to 50 oxyalkylene units, sorbitol esters and the like, for example polyoxyethylene lauryl ether, polyethylene sorbitol ether, polyoxyethylene glycerol ether and the isomeric tridecanol polyoxyethylene ethers and the like. Examples of cationic emulsifiers are emulsifiers of the quaternary ammonium type, such as alkyltrimethylammonium chlorides, dialkyldimethylammonium chlorides and alkylbenzyldimethylammonium chlorides.

The viscosity of the composition generally has a large influence on the liquid application amount (i.e., the coating amount). Too low a viscosity adversely affects the adhesion of the coating composition to the surface of the coating roll, while too high a viscosity causes too poor fluidity to deteriorate the uniformity of coating. Thus, it is common in the art to add a certain amount of thickener to the softener composition to adjust the viscosity. However, the addition of thickeners can affect the hand of the paper product and also affect the bacterial stability of the formulation. Thus, in the present invention, it is preferred that the composition comprises less than 0.1 wt%, more preferably less than 0.05 wt%, most preferably no thickener at all. Such thickeners as polyacrylic, cellulosic, alginate and guar thickeners.

The softener composition according to the invention may contain, in addition to those components mentioned above, other additives, for example 0.01-0.3% by weight of an acid for adjusting the pH, such as citric acid, phosphoric acid, acetic acid, lactic acid, hydrochloric acid, etc., and for example 0.01-0.1% by weight of a perfume for adjusting the odor. It is preferred within the scope of the invention to add those acids which are used to adjust the pH, thereby further making the treated paper milder to the skin, while also contributing to the improved emulsion stability of the composition.

Typically, in the present invention, the amount of further additives comprised in the composition, in addition to the aminopolysiloxanes of formula (I) and mono-or polyhydric alcohols and, if necessary, water, is not more than 20% by weight, preferably less than 15% by weight or less than 10% by weight, more preferably less than 5% by weight or 1% by weight or 0.5% by weight or 0.1% by weight.

A second aspect of the invention relates to a process for the preparation of said softener composition.

The softener compositions of the invention can be formulated in a simple manner by mixing the individual components with one another in the amounts indicated and stirring them thoroughly to form a stable emulsion.

In yet another aspect, the present application is directed to a method of softening paper. The treatment process is a post-finishing process, such as spraying, roll coating, printing, and the like. For example, the softener composition according to the invention can be applied directly to the surface of the paper to be treated by the above method, can be applied during the rolling or rewinding process of the paper or other processes.

In an advantageous embodiment of the paper softening process, the softener composition as described above is applied to the surface of the paper in an amount of more than 20%, preferably 25-35% by weight of the paper on a basis. Preferably, the surface distribution of the paper after coating is 0.01g/m per square meter²-3.2g/m²Preferably 0.04 to 2g/m²And 0.5-9g/m of an aminopolysiloxane²Preferably 1 to 9g/m²A hydroxyl group of (a).

Examples

1. Partial list of materials

2. Preparation of the emulsion

The components other than the alcohol component in the examples listed in the following table 1 were uniformly mixed in the amounts shown, followed by addition of a small amount of water and high-speed stirring until complete phase inversion. The remaining water was then added slowly and mixed at 300rpm for 10 minutes. Finally, the alcohol component (i.e., glycerol and/or 1,2PG) was added and stirred at 200rpm for 1 hour at 40 ℃. Examples 1 and 8 are comparative examples.

Further, example 4 was repeated to carry out comparative example 10 except that the silicone oil used in example 4 was replaced with a conventional amino silicone oil (Bluesil Ecosoft C803). The softener compositions prepared in these two examples were then tested for paper absorbency, whiteness reduction and skin substantivity as described below and the results are shown in Table 3.

3. Testing

(1) Spraying amount:

a) pouring the prepared paper towel softener into a high-pressure spray gun, and adjusting the spraying particle size and the spraying amount.

b) The weight of the towel to be treated was weighed and recorded as W0.

c) Fixing the paper towel to be treated on a spraying panel, and uniformly spraying a softening agent; the other surface of the paper towel is treated in the same way.

d) The weight of the sprayed paper towel was weighed and recorded as W1.

e) The spray amount W was calculated according to the following formulation.

f) The above steps were repeated and at least 10 treated towels were prepared for each sample.

g) The tissues are divided into two groups, one of which is stored in a self-sealing bag, and the other is placed in a balance (humidity 70-80%, room temperature 20 deg.C for 12 hr) at specified temperature and humidity.

(2) Paper properties

(i) Sensory testing

More than 5 experts professionally trained in the experiment were grouped into a panel for subjective evaluation of the experiment. Each evaluator touched the treated tissue and scored the softness of the differently treated tissue from the softest to the softest. The slipperiness and wet feel of the tissue were evaluated in a similar manner. For each performance, the sample with the worst feel was scored as 1, and more preferably, as 5.

The results of the tests are tabulated for all evaluators and for all samples and the average value of each property is calculated, the higher the value the better the softness, smoothness or wet feel.

The test data for all of the above properties are listed in table 2 below.

(ii) Water absorption test of paper towel

a) The processed paper towel is laid on the table top,

b) dropping a drop of water onto the paper towel with a standard dropper, spreading the drop of water on the paper towel until the drop of water stops spreading, recording the time of the complete spreading,

c) repeat the operation more than 5 times, take the average (second).

The higher the value, the worse the water absorption.

(iii) Paper towel whiteness test

a) The paper towel was folded in half twice to obtain 4 sheets. The whiteness values of 4 paper surfaces were measured with a colorimeter. The same operation is performed on the other side of the towel. The average whiteness value M0 of 8 faces was taken.

b) The paper towel was heated at 170 ℃ for 2 minutes, taken out and left at room temperature for 2 hours.

c) The baked towels were tested for whiteness value M1 according to step a).

d) According to the formula

Calculating the whiteness of the paper towelThe lower the reduction rate M, the better the yellowing resistance.

(iv) Skin substantivity test of paper

The products were tested according to the procedure described in the cosmetic hygiene code (department of health, 2007) (GB7919-87 cosmetic safety evaluation procedure and method), and skin substantivity was evaluated mainly on the basis of skin irritation test results, skin allergy test results, and skin phototoxicity test results. The lack of irritation, allergic response and phototoxic response is defined as good substantivity.

TABLE 1

TABLE 2

Numbering	Content of amino silicone oil, g/m²	Hydroxyl group content, g/m²	The amount of spraying is%	Flexibility	Smoothness and smoothness	Feeling of wetness
							1	0	4.046	28.9	1	1	1
2	0.190313	0.63945	29.0	3	4	4
							3	0.201469	1.692338	30.7	3.5	4.5	5
4	0.202781	3.406725	30.9	5	4.5	5
							5	0.164063	3.261563	25.0	4	5	4
6	0.196875	3.3075	30.0	4.5	5	5
							7	0.2205	3.7044	33.6	5	4.5	5
8	0.196875	0	30.0	3	2	2
							9	0.164063	3.261563	30.0	3	3	3

TABLE 3

Example numbering	Water absorption of paper in seconds	The reduction rate M of whiteness of paper, percent	Skin compatibility (good or not)
				4	3.68	19.0	Is that
10(Ref)	4.85	27.6	Whether or not

The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. It should be noted that any simple variation, modification or other equivalent substitution by a person skilled in the art without any inventive step falls within the scope of protection of the present invention, without leaving the core of the present invention.

Claims

1. A softener composition comprising, based on the total weight of the composition:

wherein

p and r are numbers greater than or equal to 0;

z represents-O-or-NR₈-, wherein R₈Having R₃The definition of (1); and

2. Softener composition according to claim 1, characterized in that the aminopolysiloxane of formula (I) satisfies at least one of the following conditions:

p and r are each independently 1 to 1000, such as 2 to 800; q is 1 to 30; the sum of p + r + q is 10-2000, more preferably 100-; r and R₁Independently of one another, represents methyl, ethyl, propyl, methoxy, ethoxy or hydroxy; r₂Represents ethylene, propylene, butylene, pentylene or hexylene; r₃Represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group or a propyl group; and/or Z represents-O-or-NR₈-, wherein R₈Is a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms such as methyl, ethyl or propyl.

3. Softener composition according to any one of the preceding claims, characterized in that R and R in the aminopolysiloxanes of formula (I)₁Independently of one another, from methyl, ethyl, methoxy or hydroxy, more preferably methyl; r₂Represents ethylene, propylene or butylene, more preferably propylene; z represents-O-; and/or R₃Represents hydrogenAn atom.

4. Softener composition according to any one of the preceding claims, characterized in that the content of other organosilicon compounds, in particular other aminopolysiloxanes different from formula (I), in the composition is not more than 5% by weight, preferably not more than 2% by weight, more preferably not more than 1% by weight, especially preferably not more than 0.5% by weight, based on the total weight of the composition.

5. Softener composition according to any of the preceding claims, characterized in that the mono-or polyhydroxy alcohol compound has the formula A- (OH)_z，

6. Softener composition according to any of the preceding claims, characterized in that the polyether segment is an aliphatic polyether segment, preferably selected from segments having 4 to 25 polyoxyethylene and/or polyoxypropylene groups.

7. Softener composition according to any of the preceding claims, characterized in that the mono-or polyhydroxy alcohol compound is selected from ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, ethylene glycol, propylene glycol, glycerol, diethylene glycol, trimethylolpropane, hexanediol, polyether polyols such as polyoxyethylene or polyoxypropylene diols or triols; preferably selected from ethylene glycol, trimethylolpropane, propylene glycol and/or glycerol.

8. Softener composition according to any of the preceding claims, characterized in that the mono-or polyhydroxy alcohol component comprises at least 95 wt.%, preferably at least 98 wt.%, more preferably at least 99 wt.%, particularly preferably 99.5 wt.% or even 100 wt.% of glycerol.

9. Softener composition according to any of the preceding claims, characterized in that the weight ratio of aminopolysiloxane to mono-or polyhydric alcohol is in the range of 0.001-0.2, preferably 0.002-0.15, more preferably 0.005-0.10, especially preferably 0.01-0.08.

10. Softener composition according to any of the preceding claims, characterized in that it comprises less than 0.1% by weight, more preferably less than 0.05% by weight, most preferably no thickener at all, preferably selected from polyacrylic, cellulosic, alginate and guar thickeners.

11. Softener composition according to any of the preceding claims, characterized in that the composition comprises 0.01-0.3% by weight of an acid for adjusting the pH, such as citric acid, phosphoric acid, acetic acid, lactic acid, hydrochloric acid.

12. A method of treating paper comprising the steps of:

a softener composition according to any one of claims 1 to 11 applied to the surface of paper in an amount of more than 20%, preferably 25% to 35% by weight of the paper on a paper basis.

13. A process according to claim 12, characterised in that the softener composition is roll coated or sprayed onto the surface of the paper.

14. Method according to any of the preceding claims, characterized in that the surface distribution of the paper after coating is 0.01g/m per square meter²-3.2g/m²Preferably 0.04 to 2g/m²And 0.5-9g/m of an aminopolysiloxane²Preferably 1 to 9g/m²A hydroxyl group of (a).

15. A paper product obtainable by the process according to any one of claims 12 to 14.